1. Field of the Invention
The present invention to be disclosed in this specification relates to a portable information processing system with the use of a head mount display (HMD).
2. Description of the Related Art
Recently, portable information terminals such as mobile computers have become popular. Utilizing such portable information terminals including mobile computers, one may access the Internet, even when he/she is neither at home nor his/her office, to gain various information and send or receive E-mail. What lies behind the popularity of such portable information terminals including mobile computers is improvement in performance of an active matrix type liquid crystal display device.
An active matrix type liquid crystal display device has a circuit called an active matrix circuit comprising: several hundred thousands to several millions of pixel regions that are arranged in matrix; and a pixel TFT (thin film transistor) that is disposed at each of the pixel regions, and controls by means of a switching function of the TFT electric charges flowing into and out of a pixel electrode that is connected to a drain electrode of each pixel TFT.
Among the active matrix circuits, there is one composed of a thin film transistor that uses an amorphous silicon film formed on a glass substrate. Also, another thin film transistor that is made of a polycrystalline silicon film and uses a quartz substrate has lately been realized to be used in an active matrix type liquid crystal display device. In this case, a peripheral drive circuit for driving a pixel TFT may be formed on the same substrate on which the active matrix circuit is formed.
The portable information terminals including mobile computers should be, as they are so named, excellent in portability. In other words, the portable information terminals including mobile computers have to be small in size and light in weight. Limitation is accordingly put on the size of the active matrix type liquid crystal display device to be used in the portable information terminals including mobile computers. Employed in recent portable information terminals is an active matrix type liquid crystal display device of about size 3 to 4 which may display an image in compliance with the VGA (640×480 pixels) standard, which sometimes fail to display enough information with that size. It has lately been normal to use even in a personal computer for general people a CRT display of 20 inch or more which may display an image in compliance with the XGA (1024×768 pixels) or the SXGA (1280×1024 pixels) standard, and it may not beyond comprehension that the above-described active matrix type liquid crystal display device, that is of about size 3 to 4 and displays an image of low resolution, is now incapable of displaying enough information. Therefore, in order to display enough information, a mobile computer needs to be equipped with an active matrix type liquid crystal display device of large size and high resolution.
However, the portable information terminals including mobile computers are required to balance the portability and high performance, and it is difficult to simultaneously satisfy the demands for downsizing and for increase in display capacity, which are incompatible.